Primary Cell Cultures Research Articles

Establishment, characterization, and genetic profiling of patient-derived osteosarcoma cells from a patient with retinoblastoma

Osteosarcoma is the most common malignant bone cancer in pediatric patients. Patients who respond poorly to chemotherapy experience worse clinical outcomes with a high mortality rate. The major challenge is the lack of effective drugs for these patients. To introduce new drugs for clinical approval, preclinical studies based on in vitro models must demonstrate the potency of the tested drugs, enabling the drugs to enter phase 1 clinical trials. Patient-derived cell culture is a promising testing platform for in vitro studies, as they more accurately recapitulate cancer states and genetic profiles compared to cell lines. In the present study, we established patient-derived osteosarcoma cells (PDC) from a patient who had previously been diagnosed with retinoblastoma. We identified a new variant of a germline mutation in the RB1 gene in the tissue of the patient. The biological effects of this PDC were studied to observe whether the cryopreserved PDC retained a feature of fresh PDC. The cryopreserved PDC preserved the key biological effects, including cell growth, invasive capability, migration, and mineralization, that define the conserved phenotypes compared to fresh PDC. From whole genome sequencing analysis of osteosarcoma tissue and patient-derived cells, we found that cryopreserved PDC was a minor population in the origin tissue and was selectively grown under the culture conditions. The cryopreserved PDC has a high resistance to conventional chemotherapy. This study demonstrated that the established cryopreserved PDC has the aggressive characteristics of osteosarcoma, in particular the chemoresistance phenotype that might be used for further investigation in the chemoresistant mechanism of osteosarcoma. In conclusion, the approach we applied for primary cell culture might be a promising method to generate in vitro models for functional testing of osteosarcoma.

Extracellular vesicles produced by HIV-1 Nef-expressing cells induce myelin impairment and oligodendrocyte damage in the mouse central nervous system

HIV-associated neurocognitive disorders (HAND) are a spectrum of cognitive impairments that continue to affect approximately half of all HIV-positive individuals despite effective viral suppression through antiretroviral therapy (ART). White matter pathologies have persisted in the ART era, and the degree of white matter damage correlates with the degree of neurocognitive impairment in patients with HAND. The HIV protein Nef has been implicated in HAND pathogenesis, but its effect on white matter damage has not been well characterized. Here, utilizing in vivo, ex vivo, and in vitro methods, we demonstrate that Nef-containing extracellular vesicles (Nef EVs) disrupt myelin sheaths and inflict damage upon oligodendrocytes within the murine central nervous system. Intracranial injection of Nef EVs leads to reduced myelin basic protein (MBP) staining and a decreased number of CC1 + oligodendrocytes in the corpus callosum. Moreover, cerebellar slice cultures treated with Nef EVs exhibit diminished MBP expression and increased presence of unmyelinated axons. Primary mixed brain cultures and enriched oligodendrocyte precursor cell cultures exposed to Nef EVs display a decreased number of O4 + cells, indicative of oligodendrocyte impairment. These findings underscore the potential contribution of Nef EV-mediated damage to oligodendrocytes and myelin maintenance in the pathogenesis of HAND.

Development and evaluation of a chicken embryo fibroblast cell culture based live attenuated Indian strain duck plague vaccine

Duck plague (DP) is an acute, contagious and fatal disease, caused by duck enteritis virus (DEV), with worldwide distribution causing several outbreaks and posing severe economic losses. The present study was carried out with a goal of development of a live attenuated cell culture based DP vaccine using an Indian strain of DEV and evaluation of its safety, efficacy along with complete genome analysis. The live attenuated DP vaccine (DPvac/IVRI-19) was developed by serial propagation of a virulent isolate of DEV (DEV/India/IVRI-2016) in the chicken embryo fibroblast (CEF) primary cell culture. Adaptation of DEV in CEF cell culture was indicated by more rapid appearance of cytopathic effects (CPE) and gradual increase of virus titre, which reached up to 107.5 TCID50/mL after 41 passages. The safety, immunogenicity and efficacy of the vaccine were determined by immunization trials in ducklings. The DPvac/IVRI-19 was found to be avirulent and completely safe in the ducklings. Further, the vaccine induced both humoral and cell mediated immune responses and afforded 100% protection against the virulent DEV challenge. A comparison of the whole genome of DPvac/IVRI-19 (MZ911871) and DEV/India/IVRI-2016 (MZ824102) revealed significant number of mutations, which might be associated with viral attenuation. Phylogenetic tree of DEV/India/IVRI-2016 revealed its evolutionary relationship with other DEV isolates, but it formed a separate cluster with certain unique mutations. Thus, with the proven safety and 100% efficacy, the DPvac/IVRI-19 is suitable for large scale production with precisely pure form of vaccine and has potential utility at national and global levels.

The Imperative for Innovative Enteric Nervous System-Intestinal Organoid Co-Culture Models: Transforming GI Disease Modeling and Treatment.

This review addresses the need for innovative co-culture systems integrating the enteric nervous system (ENS) with intestinal organoids. The breakthroughs achieved through these techniques will pave the way for a transformative era in gastrointestinal (GI) disease modeling and treatment strategies. This review serves as an introduction to the companion protocol paper featured in this journal. The protocol outlines the isolation and co-culture of myenteric and submucosal neurons with small intestinal organoids. This review provides an overview of the intestinal organoid culture field to establish a solid foundation for effective protocol application. Remarkably, the ENS surpasses the number of neurons in the spinal cord. Referred to as the "second brain", the ENS orchestrates pivotal roles in GI functions, including motility, blood flow, and secretion. The ENS is organized into myenteric and submucosal plexuses. These plexuses house diverse subtypes of neurons. Due to its proximity to the gut musculature and its cell type complexity, there are methodological intricacies in studying the ENS. Diverse approaches such as primary cell cultures, three-dimensional (3D) neurospheres, and induced ENS cells offer diverse insights into the multifaceted functionality of the ENS. The ENS exhibits dynamic interactions with the intestinal epithelium, the muscle layer, and the immune system, influencing epithelial physiology, motility, immune responses, and the microbiome. Neurotransmitters, including acetylcholine (ACh), serotonin (5-HT), and vasoactive intestinal peptide (VIP), play pivotal roles in these intricate interactions. Understanding these dynamics is imperative, as the ENS is implicated in various diseases, ranging from neuropathies to GI disorders and neurodegenerative diseases. The emergence of organoid technology presents an unprecedented opportunity to study ENS interactions within the complex milieu of the small and large intestines. This manuscript underscores the urgent need for standardized protocols and advanced techniques to unravel the complexities of the ENS and its dynamic relationship with the gut ecosystem. The insights gleaned from such endeavors hold the potential to revolutionize GI disease modeling and treatment paradigms.

Methods for assessing and removing non-specific photoimmunotherapy damage in patient-derived tumor cell culture models.

Tumor-targeted, activatable photoimmunotherapy (taPIT) has been shown to selectively destroy tumor in a metastatic mouse model. However, the photoimmunoconjugate (PIC) used for taPIT includes a small fraction of non-covalently associated (free) benzoporphyrin derivative (BPD), which leads to non-specific killing invitro. Here, we report a new treatment protocol for patient-derived primary tumor cell cultures ultrasensitive to BPD photodynamic therapy (BPD-PDT). Based on free BPD efflux dynamics, the updated invitro taPIT protocol precludes non-specific BPD-PDT by silencing the effect of free BPD. Following incubation with PIC, incubating cells with PIC-free medium allows time for expulsion of free BPD whereas BPD covalently bound to PIC fragments is retained. Administration of the light dose after the intracellular free BPD drops below the threshold for inducing cell death helps to mitigate non-specific damage. In this study, we tested two primary ovarian tumor cell lines that are intrinsically chemoresistant, yet ultrasensitive to BPD-PDT such that small amounts of free BPD (afew percent of the total BPD dose) lead to potent induction of cell death upon irradiation. The modifications in the protocol suggested here improve invitro taPIT experiments that lack invivo mechanisms of free BPD clearance (i.e., lymph and blood flow).

Protective Effects of Cannabidiol (CBD) against Qxidative Stress, but Not Excitotoxic-Related Neuronal Cell Damage-An In Vitro Study.

Cannabidiol (CBD) appears to possess some neuroprotective properties, but experimental data are still inconsistent. Therefore, this in vitro study aimed to compare the effects of CBD in a wide range of concentrations on oxidative stress and excitotoxic-related cell damage. Results showed that low concentrations of CBD ameliorated the H2O2-evoked cell damage of primary cortical neuronal cell culture. However, higher concentrations of CBD alone (5-25 μM) decreased the viability of cortical neurons in a concentration-dependent manner and aggravated the toxic effects of hydrogen peroxide (H2O2). Neuroprotection mediated by CBD in primary neurons against H2O2 was not associated with a direct influence on ROS production nor inhibition of caspase-3, but we found protective effects of CBD at the level of mitochondrial membrane potential and DNA fragmentation. However, CBD had no protective effect on the glutamate-induced cell damage of cortical neurons, and in higher concentrations, it enhanced the toxic effects of this cell-damaging factor. Likewise, CBD, depending on its concentration, at least did not affect or even enhance cortical cellular damage exposed to oxygen-glucose deprivation (OGD). Finally, we showed that CBD in submicromolar or low micromolar concentrations significantly protected human neuronal-like SH-SY5Y cells against H2O2- and 6-hydroxydopamine (6-OHDA)-induced cell damage. Our data indicate that CBD has a dual effect on oxidative stress-induced neuronal death-in low concentrations, it is neuroprotective, but in higher ones, it may display neurotoxic activity. On the other hand, in excitotoxic-related models, CBD was ineffective or enhanced cell damage. Our data support the notion that the neuroprotective effects of CBD strongly depend on its concentration and experimental model of neuronal death.

17-β-estradiol and phytoestrogens elicit NO production and vasodilatation through PI3K, PKA and EGF receptors pathways, evidencing functional selectivity

Endothelial cells express multiple receptors mediating estrogen responses; including the G protein-coupled estrogen receptor (GPER). Past studies on nitric oxide (NO) production elicited by estrogens raised the question whether 17-β-estradiol (E2) and natural phytoestrogens activate equivalent mechanisms. We hypothesized that E2 and phytoestrogens elicit NO production via coupling to distinct intracellular pathways signalling. To this aim, perfusion of E2 and phytoestrogens to the precontracted rat mesentery bed examined vasorelaxation, while fluorescence microscopy on primary endothelial cells cultures quantified single cell NO production determined following 4-amino-5-methylamino-2′,7′-difluoroescein diacetate (DAF) incubation. Daidzein (DAI) and genistein (GEN) induced rapid vasodilatation associated to NO production. Multiple estrogen receptor activity was inferred based on the reduction of DAF-NO signals; G-36 (GPER antagonist) reduced 75 % of all estrogen responses, while fulvestrant (selective nuclear receptor antagonist) reduced significantly more the phytoestrogens responses than E2. The joint application of both antagonists abolished the E2 response but not the phytoestrogen-induced DAF-NO signals. Wortmannin or LY-294002 (PI3K inhibitors), reduced by 90% the E2-evoked signal while altering significantly less the DAI-induced response. In contrast, H-89 (PKA inhibitor), elicited a 23% reduction of the E2-induced signal while blocking 80% of the DAI-induced response. Desmethylxestospongin-B (IP3 receptor antagonist), decreased to equal extent the E2 or the DAI-induced signal. Epidermal growth factor (EGF) induced NO production, cell treatment with AG-1478, an EGF receptor kinase inhibitor reduced 90% DAI-induced response while only 53% the E2-induced signals; highlighting GPER induced EGF receptor trans-modulation. Receptor functional selectivity may explain distinct signalling pathways mediated by E2 and phytoestrogens.

Air-liquid intestinal cell culture allows in situ rheological characterization of intestinal mucus.

Intestinal health heavily depends on establishing a mucus layer within the gut with physical properties that strike a balance between being sufficiently elastic to keep out harmful pathogens yet viscous enough to flow and turnover the contents being digested. Studies investigating dysfunction of the mucus layer in the intestines are largely confined to animal models, which require invasive procedures to collect the mucus fluid. In this work, we develop a nondestructive method to study intestinal mucus. We use an air-liquid interface culture of primary human intestinal epithelial cells that exposes their apical surface to allow in situ analysis of the mucus layer. Mucus collection is not only invasive but also disrupts the mucus microstructure, which plays a crucial role in the interaction between mucus and the gut microbiome. Therefore, we leverage a noninvasive rheology technique that probes the mechanical properties of the mucus without removal from the culture. Finally, to demonstrate biomedical uses for this cell culture system, we characterize the biochemical and biophysical properties of intestinal mucus due to addition of the cytokine IL-13 to recapitulate the gut environment of Nippostrongylus brasiliensis infection.

A low dose of curcumin-PDA nanoparticles improves viability and proliferation in endoneurial fibroblasts and Schwann cell cultures

Curcumin is a polyphenol extracted from Curcuma longa’s roots. Low doses of curcumin are related to anti-inflammatory, antioxidant, and neuroprotective effects, while high doses are used for their lethality. This diversity of behaviors allows us to understand curcumin as a compound with hormetic action. Due to its strongly hydrophobic character, curcumin is often solubilized in organic compounds. In this way, we have recently reported the undesirable and occasionally irreversible effects of alcohol and DMSO on the viability of primary Schwann cell cultures. In this scenario, the use of nanoparticles as delivery systems has become a successful alternative strategy for these compounds. In the present work, we describe the structure of Polydopamine (PDA) nanoparticles, loaded with a low dose of curcumin (Curc-PDA) without the use of additional organic solvents. We analyzed the curcumin released, and we found two different forms of curcumin. Small increased cell viability and proliferation were observed in endoneurial fibroblast and Schwann cell primary cultures when Curc-PDA was steadily supplied for 5 days. The increased bioavailability of this natural compound and the impact on cells in culture not only confirm the properties of curcumin at very low doses but also provide a glimpse of a possible therapeutic alternative for PNS conditions in which SCs are involved.

Isolation and Culture of Primary Human Mammary Epithelial Cells.

The mammary gland is a fundamental structure of the breast and plays an essential role in reproduction. Human mammary epithelial cells (HMECs), which are the origin cells of breast cancer and other breast-related inflammatory diseases, have garnered considerable attention. However, isolating and culturing primary HMECs in vitro for research purposes has been challenging due to their highly differentiated, keratinized nature and their short lifespan. Therefore, developing a simple and efficient method to isolate and culture HMECs is of great scientific value for the study of breast biology and breast-related diseases. In this study, we successfully isolated primary HMECs from small amounts of mammary tissue by digestion with a mixture of enzymes combined with an initial culture in 5% fetal bovine serum-DMEM containing the Rho-associated kinase (ROCK) inhibitor Y-27632, followed by culture expansion in serum-free keratinocyte medium. This approach selectively promotes the growth of epithelial cells, resulting in an optimized cell yield. The simplicity and convenience of this method make it suitable for both laboratory and clinical research, which should provide valuable insights into these important areas of study.

Abstract PO1-24-12: Investigating the immunological function of alpha-2-glycoprotein 1, zinc-binding in regulating tumor response in the breast cancer microenvironment

Abstract Purpose: Tumor immunology has attracted considerable attention as an innovative therapeutic strategy for various types of cancer. Elucidating the unique immunoregulatory mechanisms in the breast cancer microenvironment will assist in the development of novel treatment strategies. Recently, we and other researchers have found that androgen receptor (AR) expression is associated with the immunosuppressive phenotype in the breast cancer microenvironment, suggesting some immunoregulatory function in breast cancer; however, the mechanism remains unclear. Here, we focused on AR-dependent secreted protein, alpha-2-glycoprotein 1, zinc-binding (ZAG) encoded by the AZGP1 gene in breast cancer, which is structurally similar to HLA class I and is implicated in immune regulation. In this study, we investigated the immunological function of AZGP1/ZAG in the breast cancer microenvironment. Methods: We performed a gene set enrichment analysis (GSEA) to screen the biological processes associated with AZGP1 expression using a gene expression profile dataset of the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC). Subsequently, we analyzed the correlation between AZGP1 expression and the immune cell composition in breast cancer tissues estimated with the CIBERSORTx using METABRIC and another dataset of The Sweden Cancerome Analysis Network-Breast. In our previous study of 45 breast cancer tissue samples, we evaluated the infiltration of 11 types of immune cells using flow cytometry (FCM). ZAG expression was further evaluated by immunohistochemistry, and the relationship between ZAG expression and the immune cell composition in breast cancer tissue was analyzed. Based on the results of this analysis (shown in the results section) we hypothesized that ZAG has some effect on the macrophage (Mφ). The action of ZAG in M1/M2 polarization models constructed using primary culture of human peripheral blood mononuclear cells (PBMC)-derived Mφ was assessed based on the expression of M1/M2 differentiation markers (CD86, CD80/CD163, MRC1) and HLA class I/II expression evaluated by FCM (n=15 each). Results: GSEA demonstrated that AZGP1 expression was negatively correlated with multiple gene sets representing immunological processes, including inflammatory response, allograft rejection, interferon gamma response, IL6/JAK/STAT3 signaling, complement, and IL2/STAT5 signaling. Analysis by CIBERSORTx showed that AZGP1 expression was negatively correlated with the absolute score (the absolute abundance of total immune cell infiltration), Mφ M1, NK cells activated, CD4+ T memory activated, and CD8+ T (r<-3 and p< 0.05). Analyses of our in-house dataset using breast cancer tissue showed that ZAG expression was associated with decreased infiltration of monocytes/macrophages, non-classical monocytes, and myeloid-derived suppressor cells in breast cancer tissues assessed by FCM. In the in vitro analyses, ZAG decreased the expression of CD80, CD163, MRC1, and HLA classes I and II in the M1 polarization model and the expression of CD163 and MRC1 in the M2 polarization model. Conclusion: AZGP1/ZAG was associated with an immunosuppressive phenotype and reduced infiltration of specific immune cell subsets, particularly Mφ, into breast cancer tissues. In the in vitro analysis, ZAG demonstrated some regulatory effects on the phenotypic change of Mφ. Our findings strongly suggest ZAG is a novel mediator of AR-dependent immunomodulation in the breast cancer microenvironment, laying the foundation for future studies to elucidate the immunological role of ZAG in breast cancer. Citation Format: Toru Hanamura, Kozue Yokoyama, Shigehisa Kitano, Hiroshi Kagamu, Makiko Yamashita, Mayako Terao, Takuho Okamura, Nobue Kumaki, Katsuto Hozumi, Takayuki Iwamoto, Chikako Honda, Sasagu Kurozumi, Jennifer Richer, Naoki Niikura. Investigating the immunological function of alpha-2-glycoprotein 1, zinc-binding in regulating tumor response in the breast cancer microenvironment [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-24-12.

Abstract PO4-23-10: Restoring the efficacy of standard of care in treatment-refractory ER+ breast cancer by re-activation of cAMP-ROS-DNA damage axis

Abstract Estrogen receptor (ER)-positive (ER+) breast cancer has the highest incidence rate and accounts for around 75% of all cases. Endocrine therapy has been the mainstay therapy for the treatment of both early and late-stage ER+ breast cancer for decades. Although most ER+ breast cancer patients initially respond well to endocrine therapy, resistance is common. The addition of CDK4/6 inhibitors to endocrine therapy led to significant improvements in clinical outcome, and they are now considered one of the standard of care (SOC) therapies. However, a significant proportion of patients still suffer from disease relapse upon prolonged use of endocrine therapy in combination with CDK4/6 inhibitors, representing a major clinical challenge that reduces the long-term benefit and patient survival. Therefore, elucidating the mechanisms of sensitivity and resistance to SOC therapy and identifying novel actionable targets are urgently needed. Here, we show that endocrine therapies and CDK4/6 inhibitors cause toxic PARP1 trapping and generation of a functional BRCAness phenotype by downregulating key DNA repair proteins that ultimately result in increased histone parylation and reduced H3K9 acetylation, leading to transcriptional blockage and cell death. Mechanistically, we found that SOC therapy downregulates phosphodiesterase 4D (PDE4D), resulting in increased cAMP levels, PKA-dependent phosphorylation of mitochondrial COXIV-I, generation of mitochondrial reactive oxygen species (ROS), and DNA damage. Importantly, we identified PDE4D as a novel ER target gene that in turn stimulates ER activity in a feedforward loop in endocrine-responsive models and regulates BRCA1 expression. However, during SOC resistance, an ER-to-EGFR switch induces PDE4D overexpression via c-Jun. Inhibition of PDE4D using BPN14770, the first-in-class PDE4D allosteric inhibitor that has successfully completed Phase II trials in Fragile X syndrome, or its upstream EGFR in combination with SOC therapies in drug-resistant settings, including multiple acquired SOC resistant cell line models, primary cultures and organoids of endocrine resistant ER+ PDXs reinstates PARP1 trapping and BRCAness, leading to drug sensitization in vitro and in vivo. Notably, we demonstrated that high PDE4D mRNA and protein expression is associated with dramatically worse disease-free survival and overall survival in endocrine therapy-treated ER+ breast cancer. Considering the availability of potent and non-toxic PDE4D inhibitors, clinically approved EGFR and PARP1 inhibitors, our findings have great translational potential. Citation Format: Ozge Saatci, Metin Cetin, Meral Uner, Unal Metin Tokat, Ioulia Chatzistamou, Pelin Gulizar Ersan, Elodie Montaudon, Aytekin Akyol, Sercan Aksoy, Aysegul Uner, Elisabetta Marangoni, Sajish Mathew, Ozgur Sahin. Restoring the efficacy of standard of care in treatment-refractory ER+ breast cancer by re-activation of cAMP-ROS-DNA damage axis [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-23-10.

Do PFCAs drive the establishment of thyroid cancer microenvironment? Effects of C6O4, PFOA and PFHxA exposure in two models of human thyroid cells in primary culture

BackgroundExposure to environmental pollutants is suspected to be one of the potential causes accounting for the increase in thyroid cancer (TC) incidence worldwide. Among the ubiquitous pollutants, per-polyfluoroalkyl substances (PFASs), were demonstrated to exert thyroid disrupting effects. Perfluoroalkyl carboxylates (PFCAs) represent a subgroup of PFAS and include perfluoro carboxylic acids (PFOA and PFHxA) and perfluoropolyether carboxylic acid (C6O4).The potential relationship between exposure to PFCAs and TC was not yet fully elucidated.This in vitro study investigated whether certain PFCAs (C6O4, PFOA, and PFHxA) can influence the composition of TC microenvironment. MethodsTwo models of normal thyroid cells in primary cultures: Adherent (A-NHT) and Spheroids (S-NHT) were employed. A-NHT and S-NHT were exposed to C6O4, PFOA or PFHxA (0; 0.01; 0.1, 1; 10; 100; 1000 ng/mL) to assess viability (WST-1 and AV/PI assay), evaluate spherification index (SI) and volume specifically in S-NHT. CXCL8 and CCL2 (mRNA and protein), and EMT-related genes were assessed in both models after exposure to PFCAs. ResultsPFHxA reduced the viability of both A-NHT and S-NHT. None of the PFCAs interfered with the volume or spherification process in S-NHT. CXCL8 and CCL2 mRNA and protein levels were differently up-regulated by each PFCAs, being PFOA and PFHxA the stronger inducers. Moreover, among the tested PFCAs, PFHxA induced a more consistent increase in the mRNA levels of EMT-related genes. Conclusions: This is the first evaluation of the effects of exposure to PFCAs on factors potentially involved in establishing the TC microenvironment. PFHxA modulated the TC microenvironment at three levels: cell viability, pro-tumorigenic chemokines, and EMT-genes. The results provide further evidence of the pro-tumorigenic effect of PFOA. On the other hand, a marginal effect was observed for C6O4 on pro-tumorigenic chemokines.

Enhanced DNA Damage Response in a Clade of Long-Lived Bats Resolved Using Chromosome-Length Genome Assemblies

Lifespan is one of the most variable traits across the entire tree of life, and especially in mammals. Differences in lifespans between closely-related species provides a promising avenue for discovering novel pro-longevity pathways using evolutionary techniques. Previous studies focused on the evolution of longevity-associated traits, such as DNA damage response, have been hampered by a combination of low-quality genomes, low-phylogenetic coverage, or long evolutionary times, all of which can negatively affect their power to detect genes associated with longevity. In order to comprehensively study the evolution of aging and aging-associated traits in bats, we generated chromosome-level reference genomes and primary cell line libraries from a 10-million-year-old clade of 9 California Myotis species spanning a 3-fold range of lifespans. Increases and decreases in longevity independent of body size have evolved multiple times in this clade, providing a dynamic range which can be studied through functional genomics. Leveraging both genomes and cell lines, we identify several pathways specifically associated with longevity, in addition to other longevity-associated traits such as DNA repair and immunity; and show that these changes are associated with cellular resistance to various forms of chemically-induced DNA damage. These pathways represent new targets for exploration using primary cell cultures, and contribute to our understanding of how both agonistic and antagonistic pleiotropy play a role in the evolution of longevity. NSF PRFB 2109915 NIH 5R35GM142916-03. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Identification of a myofibroblast differentiation program during neonatal lung development.

Alveologenesis is the final stage of lung development in which the internal surface area of the lung is increased to facilitate efficient gas exchange in the mature organism. The first phase of alveologenesis involves the formation of septal ridges (secondary septae) and the second phase involves thinning of the alveolar septa. Within secondary septa, mesenchymal cells include a transient population of alveolar myofibroblasts (MyoFBs) and a stable but poorly described population of lipid-rich cells that have been referred to as lipofibroblasts or matrix fibroblasts (MatFBs). Using a unique Fgf18CreER lineage trace mouse line, cell sorting, single-cell RNA sequencing and primary cell culture, we have identified multiple subtypes of mesenchymal cells in the neonatal lung, including an immature progenitor cell that gives rise to mature MyoFB. We also show that the endogenous and targeted ROSA26 locus serves as a sensitive reporter for MyoFB maturation. These studies identify a MyoFB differentiation program that is distinct from other mesenchymal cell types and increases the known repertoire of mesenchymal cell types in the neonatal lung.

Juxtaglomerular (JG) cell-specific deletion of the NADPH oxidase accessory protein, NOXA1, decreases pro-renin and proteinuria in vivo in a mouse model of diabetes

A large fraction of patients with diabetes develops diabetic nephropathy. Plasma pro-renin levels are elevated in diabetic patients and thought to contribute to hypertension, renal damage and inflammation. Studying the mechanisms by which diabetes reprograms JG cells to increase pro-renin release could provide new targets for kidney disease. We previously found that JG cells from diabetic mice had higher reactive oxygen species production (superoxide and H2O2), pro-renin expression and pro-renin and renin release. We hypothesized that increased ROS production by specific NADPH oxidases (NOXs) in JG cells is responsible for higher pro-renin release and contributes to glomerular damage in diabetes. Western Blots showed that the NADPH oxidase isoform NOX1 and NOXA1 are upregulated in JG cells from diabetic mice (C57=100%; Akita=147±10%; n=4; p<0.05), whereas NOX2 or NOX4 were not different. Confocal microscopy showed that NOX1 and NOXA1 are present in JG cells and co-localize with renin-containing granules (n=3). Silencing NOX1 in primary cultures of JG cells from diabetic mice decreased renin release to C57 control levels; (n=6; p<0.01) whereas silencing NOX4 had no effect (n=6). To study the role of NOXA1 and NOX1 in JG cells in vivo, we used Cas9 mediated silencing in kidneys of control mice. Adenoviruses expressing Cas9 under control of the Ren1 promoter (AV-Ren1-Cas9) and AAV-gRNA-NOXA1 were loaded into 28-day minipumps and delivered into the renal subcapsular space in C57 mice. After 5 weeks, we obtained control (non-transduced) and Ren-Cas9-NOXA1-edited kidneys and isolated JG cells. NOXA1 expression was reduced by 60±22% in isolated JG cells and pro-renin expression was decreased by 46±19% compared to non-transduced kidneys (n=3). We then specifically deleted NOXA1 from JG cells in diabetic mice by subcapsular delivery of AV-Ren1-Cre in the kidney cortex of transgenic NOXA1 floxed diabetic Akita mice. JG cell-specific deletion of NOXA1 in diabetic mice decreased urinary ROS (8-Isoprostane pg/24hrs: Akita=4091±307; NOXA1 JG/KO=3086 ±137; n=4; p<0.05), and glomerular damage as indicated by decrease proteinuria (24h Ualbumin Akita= 98.6± 9.4; NOXA1 JG/KO= 57.8± 16.4 μg/24h; n=4; p<0.05). We conclude that enhanced NOX1/NOXA1 induced ROS in JG cells drive enhanced pro-renin release from JG cells which contribute to glomerular damage in diabetes. Thus, NOXA1/NOX1 in JG cells are a potential new target for diabetic nephropathy. DK105300-RO3 Henry Ford Hospital Institutional Funds. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Modeling Mild Traumatic Brain Injury In-Vitro Using PHuman Choroid Plexus Endothelial Cells

Over 2.5 million Traumatic Brain Injuries (TBIs) occur each year due to falls, motor vehicle accidents, assaults, and sports (Brain Trauma Foundation, 2023). Short- and long-term consequences of TBI can include headache, cognitive impairment, seizures, hypoxia, and ischemia. Human TBI studies are diffcult due to the confounding variables of type and mechanism of injury, severity of injury, and length of time to present to emergency departments. While animal models exist, it is our goal to develop an in-vitro model of TBI using primary human brain cell cultures to examine cellular responses in real time. While the blood-brain barrier has been studied extensively post-TBI due to its role in ischemia and hypoxia, there is a dearth of research on the blood-CSF-barrier (BCSFB), the choroid plexus, and its response post-TBI. After culturing primary human choroid plexus endothelial cells (ScienCell Cat #1300) on a flexible membrane, we subjected them to mechanical strain using the FlexCell tension system and collected supernatant at 3-, 6-, 12-, 24-, 48-, 72-, and 96-hours post injury. The FlexCell tension bioreactor system uses positive and negative air pressure to apply mechanical elongation strain mimicking mild shearing injury. Using R&D cytokine arrays (R&D Systems, Cat# ARY005B), we measured 36 different cytokines, chemokines and acute phase proteins including C5a, GM-CSF, ICAM-1, IL-1, IL-6, TNFα, IFNγ, CCL5/RANTES, etc. We hypothesized that we would see a pro-inflammatory response (IL-1β, IL-6, TNFα) within 24 hours after one or two 12% mechanical strain injuries compared to the control of no strain, as seen in the literature. However, there were not significant increases in cytokine signaling until 24-48 hours post-injury, and in regulatory cytokines, such as CCL2, MIP1α/MIP1β, IL-2, IL-12, & IL-17, that lasted as long as 96-hours. This effect was more pronounced in the two strain verses one strain model and control, as expected. Interestingly, anti-inflammatory cytokine IL-10 was significantly increased in the one strain model, but not two strain model, 48 hours post-insult. As the choroid plexus is a niche for T cell stimulation in the central nervous system (Strominger et al., 2018), these results indicate a complex immunological response that seems to favor T-Cell response over monocytes/macrophages. These experiments were completed with the lowest mechanical strain of the FlexCell system and future experiments are warranted to determine if a stronger mechanical strain is needed to produce the pro-inflammatory response seen in the literature in mild to severe models of TBI. This project was funded by a Senior Research Grant from the Indiana Academy of Science and from a Faculty Research Development Grant from Marian University College of Osteopathic Medicine. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

MyoD Over-expression Reprograms Elephant Seal Fibroblasts into Muscle Cells

Ex vivo tissue culture allows the study of complex cellular mechanisms that are relevant to physiological responses while overcoming the challenges presented by studying animals that are not tractable. In a primary cell culture system, certain proliferating cells can be functionally reprogrammed into other cell types via overexpression of key genes. Dermal fibroblasts can theoretically be reprogrammed into muscle cells, which are often challenging to obtain from wild organisms but offer a unique system to study metabolic responses, by overexpression of the myogenic transcription factor myoD. We derived primary dermal fibroblasts from Northern elephant seal (NES) skin samples and propagated them in primary culture. NES cells respire, stain positive for fibroblast markers (vimentin and PDGFR), and are amenable to electroporation. We overexpressed GFP-myoD in NES fibroblasts and conducted antibiotic selection and purification by FACS. As expected, expression of myoD was higher in transfected cells than in controls according to qPCR analysis (t-test p< 0.05). Treatment with small molecules (CHIR99021, Forskolin and Repsox) enhanced myoD expression. Furthermore, fibroblasts overexpressing myoD also expressed downstream myogenenic markers (myogenin, myosin heavy chain 1 and myosin heavy chain 8). MyoD-overexpressing cells differentiate into myotubes, become multinucleated and stain positively for myosin heavy chain 1. RNAseq analysis confirmed a transcriptional profile of myoD expressing cells, which is unique and different from the naive dermal elephant seal fibroblasts. Establishing differentiated muscle fibers from other mature cell types could provide a unique platform to conduct mechanistic studies in species where muscle tissue samples cannot be obtained from live animals. The Department of Defense National Defense Science and Engineering Graduate (NDSEG) Fellowship. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Life in the Slow Lane: The Rate of Protein Synthesis Is Slower in the Protoendothermic Tenrec than the Boreoeutherian Golden-Mantled Ground Squirrel

In order to address mechanisms of how hibernating mammals depress protein synthesis during torpor, we developed primary cell cultures from golden-mantled ground squirrels (Spermophilus [Callospermophilus] lateralis) and tenrecs (Tenrec ecaudatus). During torpor in squirrels, there is an acute uncoupling of translational initiation and elongation at body temperature (Tb) = 18°C as animals enter torpor. As a result, there are robust changes to the polysome profile of squirrels depending on state. Protein synthesis is depressed to 0.23 to 0.5% of active rates during torpor. In the bizarre, Afrotherian Tenrec ecaudatus, metabolism and Tb are remarkably plastic. Tenrecs may be fully active with a Tb of 12 °C or hibernating at a Tb of 28 °C. Moreover, oxygen consumption rates may vary 25 fold in active tenrecs. With this high variability in Tb, one might expect that these tenrecs might not be able to use Tb to control protein synthesis. Liver polysome profiles were confusing- there were no real changes between states or temperature. Rather, all tenrecs had a rather modest polysome profile with little heavy material typical of very active protein synthesis. To address this, we developed liver (do not grow well) and kidney cell (grow very well) cultures from ground squirrels and tenrecs. Our results indicate that the translation rate in tenrec primary cells is ~30 % of the translation rate in golden-mantled ground squirrel (p < 0.05). We interpret these results as tenrecs living ‘Life in the Slow Lane.’ By experiencing these low rates of a process critical to homeostasis, we contend tenrecs are avoiding rapid changes as a consequence of their rapid changes in Tb or metabolism. In effect, ‘driving slowly’ allows a tenrec to avoid major accidents which would imperil the animal. Perhaps not surprisingly, tenrec litters are enormous with as many as 32 confirmed young in a single litter. This research was supported by the Translational Research Institute for Space Health (TRISH). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

EcoHIV Infection of Primary Murine Brain Cell Cultures to Model HIV Replication and Neuropathogenesis.

EcoHIV is a chimeric HIV that replicates in mice in CD4+ T cells, macrophages, and microglia (but not in neurons), causing lasting neurocognitive impairment resembling neurocognitive disease in people living with HIV. The present study was designed to develop EcoHIV-susceptible primary mouse brain cultures to investigate the indirect effects of HIV infection on neuronal integrity. We used two EcoHIV clones encoding EGFP and mouse bone marrow-derived macrophages (BMM), mixed mouse brain cells, or enriched mouse glial cells from two wild-type mouse strains to test EcoHIV replication efficiency, the identity of productively infected cells, and neuronal apoptosis and integrity. EcoHIV replicated efficiently in BMM. In mixed brain cell cultures, EcoHIV targeted microglia but did not cause neuronal apoptosis. Instead, the productive infection of the microglia activated them and impaired synaptophysin expression, dendritic density, and axonal structure in the neurons. EcoHIV replication in the microglia and neuronal structural changes during infection were prevented by culture with an antiretroviral. In murine brain cell cultures, EcoHIV replication in the microglia is largely responsible for the aspects of neuronal dysfunction relevant to cognitive disease in infected mice and people living with HIV. These cultures provide a tool for further study of HIV neuropathogenesis and its control.